feat: add signed meter metadata payloads

apps/web/src/app/api/readings/route.ts

@@ -70,6 +70,14 @@ export async function GET(req: NextRequest) {
   return NextResponse.json({ data: page, next_cursor, total: count ?? 0 })
 }
 
+const MetadataSchema = z.object({
+  firmware_version: z.string().optional(),
+  hardware_model: z.string().optional(),
+  location_lat: z.number().optional(),
+  location_lon: z.number().optional(),
+  manufacturer: z.string().optional(),
+})
+
 const ReadingSchema = z.object({
   meter_id: z.string().uuid({ message: 'meter_id must be a valid UUID' }),
   kwh: z
@@ -225,6 +233,9 @@ export async function POST(req: NextRequest) {
       signature_hex,
       anchored: false,
       minted: false,
+      metadata: metadata ?? null,
+      metadata_hash: metadataHash ? metadataHash.toString('hex') : null,
+      metadata_signature_hex: metadata_signature_hex ?? null,
     })
     .select()
     .single()

docs/migrations/003_meter_metadata.sql

@@ -0,0 +1,7 @@
+-- Migration 003: add signed meter metadata columns to readings
+alter table readings
+  add column if not exists metadata jsonb,
+  add column if not exists metadata_hash text,          -- SHA-256 hex of canonical metadata JSON
+  add column if not exists metadata_signature_hex text; -- Ed25519 sig over metadata_hash (128 hex chars)
+
+create index if not exists readings_metadata_hash_idx on readings(metadata_hash);

scripts/send-reading.mjs

@@ -2,14 +2,17 @@
 /**
  * scripts/send-reading.mjs
  *
- * Simulate a smart meter sending a signed reading to the SolarProof API.
+ * Simulate a smart meter sending a signed reading (+ optional metadata) to the SolarProof API.
  *
  * Usage:
  *   node scripts/send-reading.mjs \
  *     --meter-id <uuid> \
  *     --kwh 12.5 \
  *     --key ./meter-key.json \
- *     --api http://localhost:3000
+ *     --api http://localhost:3000 \
+ *     [--firmware 1.2.3] \
+ *     [--model "SolarEdge-SE7600H"] \
+ *     [--manufacturer "SolarEdge"]
  */
 
 import { createSign, createHash } from 'crypto'
@@ -22,6 +25,9 @@ const meterId = get('--meter-id') ?? 'test-meter-id'
 const kwh = parseFloat(get('--kwh') ?? '10')
 const keyFile = get('--key') ?? './meter-key.json'
 const api = get('--api') ?? 'http://localhost:3000'
+const firmware = get('--firmware')
+const model = get('--model')
+const manufacturer = get('--manufacturer')
 
 const { private_key_hex } = JSON.parse(readFileSync(keyFile, 'utf8'))
 const timestamp = Math.floor(Date.now() / 1000)
@@ -38,9 +44,14 @@ const privKeyDer = Buffer.concat([
   Buffer.from('302e020100300506032b657004220420', 'hex'),
   Buffer.from(private_key_hex, 'hex'),
 ])
-const sign = createSign('ed25519')
-sign.update(readingHash)
-const signature = sign.sign({ key: privKeyDer, format: 'der', type: 'pkcs8' })
+
+function signHash(hash) {
+  const sign = createSign('ed25519')
+  sign.update(hash)
+  return sign.sign({ key: privKeyDer, format: 'der', type: 'pkcs8' })
+}
+
+const signature = signHash(readingHash)
 
 const body = {
   meter_id: meterId,
@@ -50,6 +61,21 @@ const body = {
   nonce: `sim-${meterId}-${timestamp}-${Math.floor(Math.random() * 1000000)}`,
 }
 
+// Attach optional signed metadata
+const metadata = {}
+if (firmware) metadata.firmware_version = firmware
+if (model) metadata.hardware_model = model
+if (manufacturer) metadata.manufacturer = manufacturer
+
+if (Object.keys(metadata).length > 0) {
+  const canonical = JSON.stringify(metadata, Object.keys(metadata).sort())
+  const metadataHash = createHash('sha256').update(Buffer.from(canonical, 'utf8')).digest()
+  const metadataSig = signHash(metadataHash)
+  body.metadata = metadata
+  body.metadata_signature_hex = metadataSig.toString('hex')
+  console.log('Metadata hash:', metadataHash.toString('hex'))
+}
+
 console.log('Sending reading:', { meterId, kwh, timestamp })
 console.log('Reading hash:', readingHash.toString('hex'))